I found the problem.

Triumpets are OK...the 675 is a badass bike, though hard to get setup correctly.

Big surprise, no check as of yet and now they are ignoring my emails.

Bike stumbles at idle and the throttle grip is very sticky. Took it apart last night, lubed it and the throttle cable, but no difference. Makes for a herky-jerky ride at low speeds, as smooth throttle imputs are impossible.

At least she's pretty...

sticky throttle issues could be the cables are bent too severe to let the cable move freely, or the adjustment on the carb/throttle body could need tweaking. as for lubing the grip, Gas Man and I have come to the conclusion that you should not lube the throttle on the handlebar. Just clean it up real good and make sure it is moving smoothly. Lube in there would just gather dirt and cause some sticky sticky. When we put the mini apes on his wifes Nightster we had to make several adjustments to how the cables were routed to make the cables slide smoothly in housings. Make sure the inside of the housings do get some cable lube and work it in really good.
The stumbling, if its carbed, could be a clogged jet. If its injected, then could be a clogged fuel rail, or injectors.
Hope this helps.

shitty on the lack of response :td:

I bought the bike with less than 600 miles showing, so I'd hoped the cables weren't worn or bent. Dry maybe, but not worn out. As for lubing the grip, I only use dry lubes (like graphite powder) for such applications.

The bike is fuel-injected. I'll be performing a full tune-up soon with plugs, air/fuel filters, etc. If it still runs rough after that, I'll try some detergent in the fuel to clean out the varnished injectors. This thing likely sat for years with the same old fuel in the tank. The fuel pump has been replaced but I'm pretty sure the filter is original.

Make sure the cables aren't too tight to the throttle bodies - that would cause the throttle to stick as well. Someone may have tried to adjust the cables and done a piss-poor job.

Seafoam

Sounds kinky.

It's been almost three months since the bike stranded me and I have yet to receive the reimbursement they promised. The dealer has been ignoring my calls, emails, and certified letters since those first few correspondences, probably just hoping I'll give up and go away.

Anyway, beware Banzai Motorsports out of Crystal Lake, Illinois. I was going to report them to the Chicago area Better Business Bureau, but it looks like several others have already done so (wish I had looked this up prior to purchase):

BBB Reliability Report for Banzai Motorsports - BBB Rating F

Some other happy customers:

Banzai Motorsports is the Worst in the Midwest

I'm out $650 in unexpected expenses related directly to their mechanical incompetence. I also feel I was lied to regarding the condition of the bike and the work they claim they performed. I may have some legal recourse, even with an as-is bike, simply because they let it go with outstanding recalls, but I doubt I'll go that route. Too complicated and it would require trips back to Illinois. Not enough money involved to warrant the effort; just enough to piss me off.

Instead, my plan is to follow every Banzai eBay listing, every Craigslist ad, every Cycletrader ad, etc that I can find and place ads of my own right alongside detailing their tactics and reputation. I'll also be posting on every message board I can find, especially forums local to Chicago.

I won't get my money back, and I may or may not interfere with their sales, but I think other potential victims deserve fair warning.

Anyone in the Chicago area willing to post fliers? :D